Condition-detecting device, method, and program, and information-recording medium

ABSTRACT

There is provided a condition detection apparatus for detecting a present operating condition of a linear rolling motion guide apparatus, and the condition detection apparatus includes an AE sensor  1  for detecting a waveform elastically generated at least due to rolling of balls included in the linear rolling motion guide apparatus and mutual collision of the balls and generating an electric detection signal corresponding the detected waveform, a waveform shaping unit  2 , an A/D converter  3 , and a signal processing unit  4  judging a content of the operation condition in response to the generated detected signal Sae.

FIELD OF THE INVENTION

The present invention relates to a technical field of conditiondetection apparatus, condition detection method, condition detectionprogram, and information recording medium, and more specifically, to atechnical filed concerning condition detection apparatus and method fordetecting a state in operation of a linear rolling motion guideapparatus when being driven and a condition detection program fordetecting the operating condition thereof, and also to a technical fieldconcerning an information recording medium recorded to be readable by acomputer.

BACKGROUND ART

In the known art, there has been widely utilized a linear rolling motionguide apparatus including a rail, a movable block moving longitudinallyon the rail, and a plurality of balls (rolling members) disposed betweenthe rail and movable block for moving the movable block at a highaccuracy while being rotating and circulating (revolving) itself. Morespecifically, such linear rolling motion guide apparatus has beenutilized for a support member supporting three-dimensional motion of awork-table of a machine tool or supporting a pendulum motion of apendulum electric car, or for an aseismatic structure of a building orlike.

According to the widening of such usable fields of the linear rollingmotion guide apparatus, there is an increased request for prevention offaults or like of the linear rolling motion guide apparatus fromcausing, and therefore, it has been required to provide a method ofdiagnosing an operation or operating condition thereof at a highaccuracy.

Incidentally, general diagnostic methods of operating conditions ofconventionally general machine systems, excluding the linear rollingmotion guide apparatus, (for example, rotational rolling bearingincluding ball bearings and like) include: a vibration detecting methodof diagnosing the operating condition by monitoring a vibrationgenerating condition in the machine system; an oil evaluation method ofdiagnosing the operating condition by evaluating a quality of alubrication oil used in the machine system; an electric resistancemethod of diagnosing the operating condition by measuring an electricresistance between members driven through the lubrication oil in themachine system; or a temperature measuring method of diagnosing theoperating condition by measuring the temperature driven through thelubrication oil in the machine system by utilizing a thermocouple.

However, in a case where these diagnostic methods are applied to thelinear rolling motion guide apparatus, the following problems have beenraised.

That is, in the case of the vibration detecting method, when used for alinear rolling motion guide apparatus in which the balls as rollingmembers revolves in a circulation path while being rotated itself, sothat many vibration generating sources exist other than an abnormalvibration generating source, and hence, the vibration which should benaturally detected cannot be accurately detected, thus providing aproblem.

Further, in the case of the oil evaluation method, it is necessary totake out, for inspection, a lubrication oil before use in the linearrolling motion guide apparatus and a lubrication oil after the usetherein, respectively, from the linear rolling motion guide apparatus asa target apparatus to be diagnosed, which requires much time forobtaining the diagnosed result, and it is also necessary to take out thelubrication oil by once stopping the operation of the linear rollingmotion guide apparatus, thus reducing the working efficiency, alsoproviding a problem.

Furthermore, the cases of the electric resistance method and thetemperature measuring method are both not suitable to electric noises,and in addition, in a case where the movable block is moved at a lowspeed, the measurement itself is difficult, thus also providing aproblem.

Accordingly, as mentioned above, in the conventional methods, it isdifficult to accurately diagnose the operation or operating conditionsof the linear rolling motion guide apparatus in a real time.

Then, present invention was therefore conceived in consideration of theabove circumstances, and an object of the present invention is toprovide a condition-detecting device and a condition-detecting methodcapable of foreseeing generation of fault in a linear rolling motionguide apparatus by accurately detecting an operation condition in a realtime in the linear rolling motion guide apparatus, improvingmaneuverability, for user, of the linear rolling motion guide apparatus,elongating a usable life time and contributing to the qualityimprovement of devices or machineries incorporated with the linearrolling motion guide apparatus, to provide a program for the conditiondetection, and to provide an information recording medium in which thecondition detection program is recorded to be readable by a computer.

DISCLOSURE OF THE INVENTION

In order to achieve the above object, the invention recited in claim 1is a condition detection apparatus for detecting a present operationcondition in a linear rolling motion guide apparatus comprising:detection means, such as AE (Acoustic Emission) sensor, for detecting awave motion elastically generated on the basis of at least either one ofcontact or collision of a movable member or a track member to a rollingmember contained in the linear rolling motion guide apparatus, contactor collision of a rolling surface to the rolling member contained in thelinear rolling motion guide apparatus, or mutual contact or collision ofthe rolling members themselves, at a time when a plurality of rollingmembers contained in the linear rolling motion guide apparatus revolvein a circulation section therein, and generating an electric detectionsignal in accordance with the detected wave motion; and judgment means,such as signal processing unit, for judging a content of the presentoperation condition in response to the generated detection signal.

Accordingly, since the wave motion elastically generated by theoperation of the linear rolling motion guide apparatus is detected tothereby detect the present operating condition thereof, the operatingcondition of the linear rolling motion guide apparatus can be detectedin a real time without disassembling the apparatus while excludinginfluence of vibration caused by the operation of the apparatus.

In order to achieve the above object, the invention of claim 2 is thecondition detection apparatus of claim 1, in which the judgment meanscomprises: periodicity judgment means, such as signal processing unit,for judging presence or absence of a periodicity in the generateddetection signal; maximum value detection means, such as signalprocessing unit, for detecting a maximum value in the generateddetection signal at a time when it is judged that the periodicity ispresent; maximum value judgment means, such as signal processing unit,for judging whether or not the detected maximum value is not less than apreliminarily set threshold value of the maximum value; and conditionjudgment means, such as signal processing unit, for judging that, whenthe detected maximum value is not less than the threshold value of themaximum value, the linear rolling motion guide apparatus falls in alubrication fault condition and then announcing that fact.

Accordingly, in the case when the generated detected signal has theperiodicity and the maximum value at the detected signal is not lessthan the threshold value of the maximum value, it is judged that thelinear rolling motion guide apparatus falls in a lubrication faultcondition and that fact is then announced, so that the generation of thelubrication fault in the linear rolling motion guide apparatus can beeasily and precisely detected in a real time during the operation of theapparatus.

In order to achieve the above object, the invention of claim 3 is thecondition detection apparatus of claim 1, in which the judgment meanscomprises: periodicity judgment means, such as signal processing unit,for judging presence or absence of a periodicity of the generateddetection signal; maximum value detection means, such as signalprocessing unit, for detecting a maximum value in the generateddetection signal at a time when it is judged that the periodicity ispresent; maximum value judgment means, such as signal processing unit,for judging whether or not the detected maximum value is not less than apreliminarily set threshold value of the maximum value; event ratiodetection means, such as signal processing unit, for detecting an eventratio in the generated detection signal at a time when the detectedmaximum value is less than a threshold value of the maximum value; eventratio judgment means, such as signal processing unit, for judgingwhether or not the detected event ratio is not less than a preliminarilyset threshold value of the event ratio; and condition judgment means,such as signal processing unit, for judging that, when the detectedevent ratio is less than the threshold value of the event value, thelinear rolling motion guide apparatus is in a possibility of falling ina lubrication fault condition and then announcing that fact.

Accordingly, when the generated detected signal has the periodicity, themaximum value in the detected signal is less than the threshold value ofthe maximum value and the detected event ratio is less than thethreshold value of the event value, it is judged that the linear rollingmotion guide apparatus is in a possibility of falling in a lubricationfault condition and that fact is then announced, so that the possibilityof the generation of the lubrication fault in the linear rolling motionguide apparatus can be detected easily and precisely in a real timeduring the operation of the apparatus.

In order to achieve the above object, the invention of claim 4 is thecondition detection apparatus of claim 1, in which the judgment meanscomprises: periodicity judgment means, such as signal processing unit,for judging presence or absence of a periodicity of the generateddetection signal; maximum value detection means, such as signalprocessing unit, for detecting a maximum value in the generateddetection signal at a time when it is judged that the periodicity ispresent; maximum value judgment means, such as signal processing unit,for judging whether or not the detected maximum value is not less than apreliminarily set threshold value of the maximum value; event ratiodetection means, such as signal processing unit, for detecting an eventratio in the generated detection signal at a time when the detectedmaximum value is less than a threshold value of the maximum value; eventratio judgment means, such as signal processing unit, for judgingwhether or not the detected event ratio is not less than a preliminarilyset threshold value of the event ratio; and condition judgment means,such as signal processing unit, for judging that, when the detectedevent ratio is not less than the threshold value of the event value, aflaking is generated in the linear rolling motion guide apparatus andthen announcing that fact.

Accordingly, when the generated detected signal has the periodicity, themaximum value in the detected signal is less than the threshold value ofthe maximum value and the detected event ratio is not less than thethreshold value of the event value, it is judged that a flaking isgenerated in the linear rolling motion guide apparatus and that fact isthen announced, so that the generation of the flaking in the linearrolling motion guide apparatus can be detected easily and precisely in areal time during the operation of the apparatus.

In order to achieve the above object, the invention of claim 5 is thecondition detection apparatus of claim 1, in which the judgment meanscomprises: periodicity judgment means, such as signal processing unit,for judging presence or absence of a periodicity of the detecteddetection signal; effective value detection means, such as signalprocessing unit, for detecting an effective value of the detecteddetection signal at a time when it is judged that the periodicity isabsent; effective value judgment means, such as signal processing unit,for judging whether or not the detected effective value is not less thana preliminarily set threshold value of the effective value; andcondition judgment means, such as signal processing unit, for judgingthat, when the detected effective value is not less than the thresholdvalue of the effective value, a foreign material invades in the linearrolling motion guide apparatus and then announcing that fact.

Accordingly, when the generated detected signal has no periodicity, andthe effective value in the detected signal is not less than thethreshold value of the effective value, it is judged that a foreignmaterial is invaded in the linear rolling motion guide apparatus andthat fact is then announced, so that the generation of the case of theinvasion of the foreign material in the linear rolling motion guideapparatus can be detected easily and precisely in a real time during theoperation of the apparatus.

In order to achieve the above object, the invention of claim 6 is thecondition detection apparatus of claim 1, in which the judgment meanscomprises: periodicity judgment means, such as signal processing unit,for judging presence or absence of a periodicity of the detecteddetection signal; effective value detection means, such as signalprocessing unit, for detecting an effective value of the detecteddetection signal at a time when it is judged that the periodicity isabsent; effective value judgment means, such as signal processing unit,for judging whether or not the detected effective value is not less thana preliminarily set threshold value of the effective value; andcondition judgment means, such as signal processing unit, for judgingthat, when the detected effective value is less than the threshold valueof the effective value, a present operation condition is normal, andthen announcing that fact.

Accordingly, when the generated detected signal has no periodicity andthe effective value in the detected signal is less than the thresholdvalue of the effective value, it is judged that the present operatingcondition is normal and that fact is then announced, so that it can bedetected easily and precisely in a real time whether or not theoperating condition in the linear rolling motion guide apparatus isnormal.

In order to achieve the above object, the invention of claim 7 is thecondition detection method for detecting the present operating conditionin the linear rolling motion guide apparatus, comprising: a detectionstep for detecting a wave motion elastically generated on the basis ofat least either one of contact or collision of a movable member or atrack member to a rolling member contained in the linear rolling motionguide apparatus, contact or collision of a rolling surface to therolling member contained in the linear rolling motion guide apparatus,or mutual contact or collision of the rolling members themselves, at atime when a plurality of rolling members contained in the linear rollingmotion guide apparatus revolve in a circulation section therein, andgenerating an electric detection signal in accordance with the detectedwave motion; and a judgment step for judging a content of the presentoperation condition in response to the generated detection signal.

Accordingly, since the wave motion elastically generated by theoperation of the linear rolling motion guide apparatus is detected tothereby detect the present operating condition thereof, the operatingcondition of the linear rolling motion guide apparatus can be detectedin a real time without disassembling the apparatus while excludinginfluence of vibration caused by the operation of the apparatus.

In order to achieve the above object, the invention of claim 8 is thecondition detection method of claim 7, in which the judgment stepcomprises: a periodicity judgment step for judging presence or absenceof a periodicity in the generated detection signal; a maximum valuedetection step for detecting a maximum value in the generated detectionsignal at a time when it is judged that the periodicity is present; amaximum value judgment step for judging whether or not the detectedmaximum value is not less than a preliminarily set threshold value ofthe maximum value; and a condition judgment step for judging that, whenthe detected maximum value is not less than the threshold value of themaximum value, the linear rolling motion guide apparatus falls in alubrication fault condition and then announcing that fact.

Accordingly, in the case when the generated detected signal has theperiodicity and the maximum value at the detected signal is not lessthan the threshold value of the maximum value, it is judged that thelinear rolling motion guide apparatus falls in a lubrication faultcondition and that fact is then announced, so that the generation of thelubrication fault in the linear rolling motion guide apparatus can beeasily and precisely detected in a real time during the operation of theapparatus.

In order to achieve the above object, the invention of claim 9 is thecondition detection method of claim 7, in which the judgment means stepcomprises: a periodicity judgment step for judging presence or absenceof a periodicity of the generated detection signal; a maximum valuedetection step for detecting a maximum value in the generated detectionsignal at a time when it is judged that the periodicity is present; amaximum value judgment step for judging whether or not the detectedmaximum value is not less than a preliminarily set threshold value ofthe maximum value; an event ratio detection step for detecting an eventratio in the generated detection signal at a time when the detectedmaximum value is less than a threshold value of the maximum value; anevent ratio judgment step for judging whether or not the detected eventratio is not less than a preliminarily set threshold value of the eventratio; and a condition judgment step for judging that, when the detectedevent ratio is less than the threshold value of the event value, thelinear rolling motion guide apparatus is in a possibility of falling ina lubrication fault condition and then announcing that fact.

Accordingly, when the generated detected signal has the periodicity, themaximum value in the detected signal is less than the threshold value ofthe maximum value and the detected event ratio is less than thethreshold value of the event value, it is judged that the linear rollingmotion guide apparatus is in a possibility of falling in a lubricationfault condition and that fact is then announced, so that the possibilityof the generation of the lubrication fault in the linear rolling motionguide apparatus can be detected easily and precisely in a real timeduring the operation of the apparatus.

In order to achieve the above object, the invention of claim 10 is thecondition detection method of claim 7, in which the judgment stepcomprises: a periodicity judgment step for judging presence or absenceof a periodicity of the generated detection signal; a maximum valuedetection step for detecting a maximum value in the generated detectionsignal at a time when it is judged that the periodicity is present; amaximum value judgment step for judging whether or not the detectedmaximum value is not less than a preliminarily set threshold value ofthe maximum value; an event ratio detection step for detecting an eventratio in the generated detection signal at a time when the detectedmaximum value is less than a threshold value of the maximum value; anevent ratio judgment step for judging whether or not the detected eventratio is not less than a preliminarily set threshold value of the eventratio; and a condition judgment step for judging that, when the detectedevent ratio is not less than the threshold value of the event value, aflaking is generated in the linear rolling motion guide apparatus andthen announcing that fact.

Accordingly, when the generated detected signal has the periodicity, themaximum value in the detected signal is less than the threshold value ofthe maximum value and the detected event ratio is not less than thethreshold value of the event value, it is judged that a flaking isgenerated in the linear rolling motion guide apparatus and that fact isthen announced, so that the generation of the flaking in the linearrolling motion guide apparatus can be detected easily and precisely in areal time during the operation of the apparatus.

In order to achieve the above object, the invention of claim 11 is thecondition detection method of claim 7, in which the judgment stepcomprises: a periodicity judgment step for judging presence or absenceof a periodicity of the detected detection signal; an effective valuedetection step for detecting an effective value of the detecteddetection signal at a time when it is judged that the periodicity isabsent; an effective value judgment step for judging whether or not thedetected effective value is not less than a preliminarily set thresholdvalue of the effective value; and a condition judgment step for judgingthat, when the detected effective value is not less than the thresholdvalue of the effective value, a foreign material invades in the linearrolling motion guide apparatus and then announcing that fact.

Accordingly, when the generated detected signal has no periodicity, andthe effective value in the detected signal is not less than thethreshold value of the effective value, it is judged that a foreignmaterial is invaded in the linear rolling motion guide apparatus andthat fact is then announced, so that the generation of the case of theinvasion of the foreign material in the linear rolling motion guideapparatus can be detected easily and precisely in a real time during theoperation of the apparatus.

In order to achieve the above object, the invention of claim 12 is thecondition detection method of claim 7, in which the judgment stepcomprises: a periodicity judgment step for judging presence or absenceof a periodicity of the detected detection signal; an effective valuedetection step for detecting an effective value of the detecteddetection signal at a time when it is judged that the periodicity isabsent; an effective value judgment step for judging whether or not thedetected effective value is not less than a preliminarily set thresholdvalue of the effective value; and a condition judgment step for judgingthat, when the detected effective value is less than the threshold valueof the effective value, a present operation condition is normal and thenannouncing that fact.

Accordingly, when the generated detected signal has no periodicity andthe effective value in the detected signal is less than the thresholdvalue of the effective value, it is judged that the present operatingcondition is normal and that fact is then announced, so that it can bedetected easily and precisely in a real time whether or not theoperating condition in the linear rolling motion guide apparatus isnormal.

In order to achieve the above object, the invention of claim 13 is acondition detection program, wherein a condition detection apparatus fordetecting a present operation condition in a linear rolling motion guideapparatus, which includes detection means for detecting a wave motionelastically generated on the basis of at least either one of contact orcollision of a movable member or a track member to a rolling membercontained in the linear rolling motion guide apparatus, contact orcollision of a rolling surface to the rolling member contained in thelinear rolling motion guide apparatus, or mutual contact or collision ofthe rolling members themselves, at a time when a plurality of rollingmembers contained in the linear rolling motion guide apparatus revolvein a circulation section therein, and generating an electric detectionsignal in accordance with the detected wave motion, includes a computerwhich is operated as judgment means for judging a content of theoperation condition in response to the generated detected signal.

Accordingly, since the computer functions so as to detect the wavemotion elastically generated by the operation of the linear rollingmotion guide apparatus and to thereby detect the present operatingcondition thereof, the operating condition of the linear rolling motionguide apparatus can be detected in a real time without disassembling theapparatus while excluding influence of vibration caused by the operationof the apparatus.

In order to achieve the above object, the invention of claim 14 is aninformation recording medium, wherein the condition detection program asclaimed in claim 13 is recorded to be readable by the computer.

Accordingly, at the time of reading out and executing the program forthe condition detection by utilizing the computer, since the computerfunctions so as to detect the wave motion elastically generated by theoperation of the linear rolling motion guide apparatus and to therebydetect the present operating condition thereof, the operating conditionof the linear rolling motion guide apparatus can be detected in a realtime without disassembling the apparatus while excluding influence ofvibration caused by the operation of the apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is one for explaining the principle of the present invention, inwhich (a) and (b) are views showing generation of en extended AE waveaccording to an embodiment of the present invention and (c) is oneexample of envelope detection wave-shape corresponding to the extendedAE wave.

FIG. 2 is a block diagram showing a structure of the condition detectionapparatus according to the embodiment of the present invention.

FIG. 3 is a elevational section of an AE sensor according to theembodiment of the present invention.

FIG. 4 is one (I) representing an installation example of the AE sensoraccording to the embodiment of the present invention, in which (a) is aperspective view of an outer appearance showing a structure of an LMsystem including a movable block, (b) is a perspective view showing aninner structure thereof, and (c) is a side view of an outer appearanceof one example of a position in a case where the AE sensor is set to theLM system.

FIG. 5 is a side view of the LM system including the movable blockaccording to the embodiment of the present invention.

FIG. 6 is one (II) representing an installation example of the AE sensoraccording to the embodiment of the present invention, in which (a) is aperspective view of an outer appearance showing a structure of an LMsystem including a ball screw and (b) is a side view of an outerappearance of one example of a position in a case where the AE sensor isset to the LM system.

FIG. 7 shows a flowchart representing an operating condition detectionprocedure.

BEST MODE FOR EMBODYING THE INVENTION

Hereunder, a preferred embodiment of the present invention will bedescribed with reference to the accompanying drawings.

Further, embodiments described hereinafter are ones in which the presentinvention is applied to detection and diagnosis of an operational (oroperating) condition in a linear rolling motion guide apparatus(hereinafter, merely called LM “Linear Motion” System, morespecifically, including a linear motion system such as so-called an LMguide, ball spline and the like).

(I) Principle of the Invention

First, in advance of the concrete explanation of the embodiment of thepresent invention, the principle of the present invention will bedescribed with reference to FIG. 1.

In a study of a diagnosis method of operating condition of an LM systemof the type mentioned above, the inventor of the subject application wasfound that so-called an AE phenomenon could be utilized for thediagnosis of the operating condition of the LM system utilized for thediagnosis of fault of a conventional rolling roller bearing device.

That is, the inventor of the present invention was found throughexperiments that mutually different AE waves were caused in a case wherethe AE phenomena of different modes are caused with respect to variousabnormal operating conditions (specifically, generation of lubricationdefect and flaking (that is, peeling phenomenon on a ball surface asrolling member included in the LM system, or a guide surface as a trackmember to which the ball contacts), or mixing of foreign material), andaccording to such causing, various abnormal operating conditions werecaused.

Here, such AE phenomena or phenomenon was defined in a conventionaltechnology, as “phenomenon generating acoustic emission wave (AE wave)by releasing an elastic energy in accordance with destroy or deformationof a solid material” or “phenomenon generating an elastic wave followingplastic deformation or crack generation inside a material”. The inventorof the subject application, however, confirmed in addition thereto thatthe AE wave is also generated only by mutual collision of balls causedby the normal operation of the LM system through any plastic deformationor crack is not generated on the ball or guide surface.

More specifically, in the case of the LM system utilizing the movableblock, as shown in FIG. 1( a), the ball B revolves, while rotating, inthe rolling path formed in the movable block C, it was confirmed by theinventor that the AE wave is generated in each of the cases when theballs B collide with each other at the contact point P1, when the ball Band the movable block C collide at the contact point P2, and when theball B and the rolling surface G collide at the contact point P3.

Further, as shown in FIG. 1( b), with respect to the case of the LMsystem utilizing the movable block, even in the case where not only theball B but also so-called a retainer R is disposed in the rolling path,if the ball B revolves, while rotating, in the rolling path formed inthe movable block C, it was confirmed by the inventor that the AE waveis generated in each of the cases when the ball B and the movable blockC collide with each other at the contact point P5 and when the ball Band the rolling surface G collide with each other at the contact pointP4.

The inventor then found that the generation modes of such AE waves weredifferent from each other in accordance with kinds or types of theabnormal operating conditions mentioned hereinabove.

Further, as mentioned above, in the present invention, the generation ofthe AE phenomenon in a range wider than that of the AE phenomenonaccording to the conventional definition is promised, so that, in thefollowing description, the AE phenomenon applied to the presentinvention is referred to as extended AE phenomenon, and the AE wavegenerated based on this extended AE phenomenon is referred to asextended AE wave.

Further, an electric signal corresponding to the extended AE wave has afrequency higher than a vibration or oscillation generally generated atan operating period of the LM system, and accordingly, for example, asshown in FIG. 1( c), it is possible to detect it separately from thatvibration by the so-called envelope detection wave method, and it isthereby possible to detect the operating condition in real time duringthe operation of the LM system.

(II) Exemplary Embodiment

Hereunder, the exemplary embodiment of the present invention based onthe above principle will be specifically explained with reference toFIGS. 2 to 7.

Herein, FIG. 2 is a block diagram showing a general structure of acondition diagnosis apparatus according to the embodiment of the presentinvention, FIG. 3 is an elevational section showing a general structureof an AE sensor detecting the extended AE wave according to theembodiment of the present invention, FIGS. 4 to 6 are views forexplaining the LM system to which the present invention is applied, andFIG. 7 shows a flowchart representing an operating condition detectionprocedure executed by the condition diagnosis apparatus according to thepresent embodiment.

As shown in FIG. 2, a condition diagnosis apparatus S according to thepresent embodiment comprises an AE sensor 1, a waveform shaping unit 2including a BPF (Band Pass Filter) 2A and an envelope detection section2B, an A/D (analog-to-digital) converter 3, a signal processing unit 4serving as periodicity judging means, maximum value detecting means,maximum value judging means, condition judging means, event detectionmeans, event judging means, effective value detecting means andeffective value judging means, and a display unit 5 including a liquidcrystal display and the like.

Next, operation of the embodiment will be described.

First, the AE sensor 1 is disposed at an optional position of the LMsystem which is an object to be diagnosed, for example, an end positionof a rail or a position on a movable block as a movable member. The AEsensor 1 detects the extended AE wave generated by the operation of theLM system and outputs the detected AE wave to the waveform shaping unit2 after the conversion into a detection signal Sae as analog signal.

Next, the BPF 2A in the waveform shaping unit 2 serves to remove afrequency component other than the extended AE wave from the detectionsignal Sae and generate it to the envelope detection section 2B. Herein,it is desirable to use an BPR, for example as a concrete example of thisBPF 2A, capable of passing the frequency component more than 100 kHz andless than 1 MHz as pass frequency band area with respect to thedetection signal Sae in this BPF 2A.

The envelope detection section 2B serves to extract the envelopecomponent based on the detection signal Sae and create an envelopesignal Sw, which is then sent to the A/D converter 3.

Next, the A/D converter 3 serves to digitalize the envelope signal Sw asanalog signal and create a digital envelope signal Sdw, which is thensent to the signal processing unit 4.

The signal processing unit 4 serves to judge the present operation(operating) condition in the LM system as the object to be diagnosed bythe operation condition detection processing shown in FIG. 7, describedhereinlater, based on the digital envelope signal Sdw, and a resultingjudgment signal Sdp is created, which is then outputted to the displayunit 5.

According to the operations mentioned above, the display unit 5 servesto display its content based on the judgment signal Sdp, thereby makingit possible to grasp the operating condition of the LM system by a userthereof.

Next, the structure of the AE sensor 1 and its setting mode to the LMsystem as the object to be diagnosed will be explained hereunder withreference to FIGS. 3 to 6.

An inside structure of the AE sensor 1 will be first described withreference to FIG. 3.

As shown in FIG. 3, the AE sensor 1 has a circular cylindrical shape inits entire structure, and more specifically, is composed of a contactportion 10 arranged so as to contact a rail LM or like in the LM system,a casing 11, a piezoelectric element 13, silver evaporated thin films 12and 14 deposited on upper and lower surfaces of the piezoelectricelement 13, and an external line 15 through which the detection signalSae, mentioned above, is outputted to the waveform shaping unit 2.

When the extended AE wave generated inside the LM system is transferredto the piezoelectric element 13 via the contact portion 10 and thesilver thin film 14, the shape of the piezoelectric element 13 isminutely deformed by the extended AE wave, and hence, an electricpotential difference is caused between the silver thin films 12 and 14,thus generating the detection signal Sae on the external line 15.

The AE sensor 1 having the structure mentioned above is installed to theLM system in the following manner with reference to FIGS. 4 to 6.Further, FIG. 4 and FIG. 5 are views representing examples at a time ofinstalling the AE sensor 1 to the LM system using the movable block asan object to be diagnosed, and FIG. 6 is a view representing an exampleat a time of installing the AE sensor 1 to the LM system using the ballscrew as an object to be diagnosed.

First, the case where the AE sensor 1 is mounted to the LM sensorutilizing the movable block will be explained with reference to FIGS. 4and 5.

The LM system shown in FIGS. 4( a) and (b) is composed of a rail 20provided with ball rolling grooves 20 a and 20 b along which balls 22roll in the longitudinal direction as mentioned later, a movable block21 engaged with the rail 20 through the number of balls 22 and provided,in its inside, with an endless circulation passage of the balls 22, andseal members 23 applied to both end surfaces of the movable block 21 inits moving direction so as to seal the upper and both side surfaces ofthe rail 20, and according to the circulation of the balls 22, themovable block 21 is reciprocally moved on the rail 20.

As shown in these figures, the rail 20 has substantially a rectangularshape in section and formed with attachment holes 24 for insertingfastening bolts, the holes being formed through out the rail 20 in itslongitudinal direction at an appropriate interval between adjacent ones.In addition, two rows of ball rolling grooves 20 a are formed on theupper surface of the rail 20 so as to sandwich the attachment holes 24therebetween, and on the other hand, further two rows of ball rollinggrooves 20 b are formed to the side surfaces of the rail 20,respectively. These four rows of ball rolling grooves are formed with aradius of curvature slightly larger than the radius of curvature of thespherical surface of the ball 22 so as to provide a relatively deepgrope shape.

On the other hand, the movable block 21 is composed of a block body 26provided with a mount surface 25 to which a movable member such as table30, mentioned hereinlater, is mounted, and a pair of end plates 27, 27fixed to both longitudinal end surface portions of the block body 26,and the lower side of the movable block 21 has a straddle shape, insection, having a recessed portion in its lower side into which the rail20 is idly fitted.

Then, as shown FIG. 5, the block body 26 has a pair of skirt portionsextending downward from a base, to which the mount surface 25 mentionedbefore is formed, or both the end portions of the base so as to providea saddle shape in section, and four rows of loaded rolling grooves 28are formed to the inside surfaces of the skirt portions and the lowersurface of the rail 20 so as to correspond respectively to the ballrolling grooves 20 a and 20 b formed thereto. The balls 20 roll betweenthe loaded rolling grooves 28 and the ball rolling grooves 20 a and 20 bwhile being loaded, whereby the movable block 21 is moved on the rail20.

Now, back to FIGS. 4( a) and (b), the base and the skirt portions of theblock body 26 are pierced as ball return bores 29 corresponding to theloaded rolling grooves 28, respectively, and these ball return bores 29are coupled and communicated with the loaded rolling grooves 28,respectively, through direction changing passages having substantiallyU-shape, not shown, formed to the end plates 27, 27. That is, thedirection changing passages scoop up balls 22 which have rolled on theloaded rolling grooves 28 of the block body 26 and feed the balls 22 tothe ball return bores 29, and on the other hand, the direction changingpassages also serve to feed the balls 22 from the ball return bores 29again to the loaded rolling grooves 28. Accordingly, by fastening theend plates 27, 27 to the block body 26 by means of fastening bolts 21 a,21 a, the endless circulation passage for the balls 22 is formed to themovable block 21.

Further, when the AE sensor 1 of the present embodiment is set to the LMsystem shown in FIGS. 4( a) and (b), as shown in FIG. 4( c) as an outerappearance side view, for example, in the case where the table 30 is seton a plurality of movable blocks 21 which linearly move on the trackrail 20, the AE sensor 1 is placed on a position of the rail 20 outsidethe moving range of the movable block 21.

Next, the case where the AE sensor 1 is set to the LM system utilizingthe ball screw will be explained with reference to FIG. 6.

As shown in FIG. 6( a), a ball screw 40 is provided with a screw shaft41 having an outer peripheral surface in which a spiral ball rollinggroove 41 a is formed, a nut member 42 having an inner peripheralsurface in which a spiral loaded rolling groove 42 a is formed so as tocorrespond to the spiral ball rolling groove 41 a, and a number of balls43, 43,—rolling between the ball rolling groove 41 a and the loadedrolling groove 42 a. A loaded rolling passage is formed by and betweenhe ball rolling groove 41 a of the screw shaft 41 and the loaded rollinggroove 42 a of the nut member 42. The nut member 42 is mounted with tworeturn pipes 44 as circulation members. The return pipes 44 connect oneand the other ends of the loaded rolling passage so as to constitute anon-loaded return passage. The return pipes 44 has substantiallygate-shaped arrangement having a central portion 44 a and a pair of legportions 44 b, 44 b on both sides of the central portion 44 a. Thepaired leg portions 44 b, 44 b are inserted into the loaded rollingpassage at a several-pitch interval. The return pipes 44 are fixed tothe nut member 42 by coupling means such as bolts 45.

The spiral ball rolling groove 41 a of the screw shaft 41 is formed,through a grinding working, rolling working or like working, in theouter peripheral surface thereof so as to provide a semi-circular crosssection with a constant lead. The nut member 42 has substantially acylindrical shape and is provided with a flanged portion 46 at one endfor mounting the ball screw 40 to a machine or like. The loaded rollinggroove 42 a having a semi-circular sectional shape corresponding to theball rolling groove 41 a of the screw shaft 41 is formed to the innerperipheral surface of the nut member 42. The nut member 42 is providedwith a flat surface portion 47 partially of an upper surface. Aplurality of return pipe fitting holes, into which the leg portions 44b, 44 b of the return pipes 44 are inserted, are formed to the flatsurface portion 47 of the nut member 42.

Then, when the AE sensor 1 of the present embodiment is set to the LMsystem shown in FIG. 6( a), in the case where the ball screw 41 drivenby a motor 48 is rotatably supported by a table 49, for example, asshown in FIG. 6( b) as an outer appearance view, and a table 51 is fixedto the ball screw 40 through a bracket 50, the AE sensor 1 is mounted toa surface of the flanged portion 46 perpendicular to the central axis ofthe ball screw 40.

In the followings, the operating condition detection processingaccording to the embodiment executed mainly by the signal processingunit 4 will be explained with reference to FIGS. 1, 2 and 7.

As shown in FIG. 7, in the case when the operating condition detectionprocessing according to the embodiment of the present invention isexecuted during the operation of the LM guide being the object to bediagnosed, a required initial setting processing is first carried out.Next, the extended AE wave generated in accordance with the extended AEphenomenon during the LM system operation is detected by the AE sensor 1(step S1), the detection signal Sae generated in response to thedetected AE wave is subjected to the waveform shaping in the waveformshaping unit 2 (step S2), and the envelope signal Sw is created and sentas digital envelope signal Sdw, through the A/D converter 3, to thesignal processing unit 4. Thereafter, the extended AE wave detectionprocedure (step S1) and the waveform shaping procedure (step S2) arerepeated by required inspection times to thereby store the dataconcerning the digital envelope signal Sdw in a memory, not shown, inthe signal processing unit 4 (step S3), and a parameter utilizing forrespective judgments or discriminations are operated based on the storeddata, which is then stored in the memory (step S4).

In this embodiment, this parameter specifically includes four parametersrepresenting: presence or absence of periodicity of the data of thedigital envelope signal Sdw; a maximum value in the digital envelopsignal data in the detection period preliminarily set in accordance withthe moving distance and moving speed in one direction in the movableblock reciprocating motion, for example, included in the LM system as anobject to be diagnosed; an effective value in the detection period; andthe event ratio in the detection period.

More specifically, the periodicity of the data of the digital envelopesignal Sdw is one that detected by means of frequency analysis of thefrequency repeating contact to and separation from a rail surface in thecase that the ball revolves in accordance with the operation of the LMsystem, which is specific to the case of detecting the operatingcondition of the LM system.

Further, the effective value mentioned above is obtained by squaring andthen averaging the values of the digital envelope signals Sdw withrespect to the detection period thereof.

Furthermore, the event ratio mentioned above is a parameter thatrepresents the times (numbers), in one detection period, in which thevalue of the digital envelope signal Sdw exceeds the preset thresholdvalue.

Upon the completion of the operation or calculation and accumulation ofthe respective parameters, it is judged or discriminated, in the signalprocessing unit 4, whether or not there exists the periodicity withrespect to the values of the digital envelope signal Sdw with referenceto the preset frequency analysis value (step S5).

In the judgment in the step S5, in a case that the periodicity is notdetected, (i.e., NO, in step S5), the effective value of the digitalenvelope signal Sdw is called up from the memory (step S6).

Then, it is judged whether the call-up effective value exceeds thethreshold value of the effective value as a threshold value which wasexperimentally preset for the judgment whether a foreign material isincluded or operation is normally performed (step S7).

Next, in the judgment in the step S7, in a case that the called-upeffective value is less than the threshold value of the effective value(i.e., NO in step S7), it is judged that the LM system now as an objectto be diagnosed is normally operated at the present stage (step S8), andthis effect is displayed by using the display unit 5 (step S10). Then, aseries of operation (operating) condition detection procedures has beencompleted.

On the other hand, in the judgment in the step S7, in the judgment inthe step S7, in a case that the called-up effective value is not lessthan the threshold value of the effective value (i.e., YES in step S7),it is judged that any foreign material is included in the LM system asan object to be diagnosed (step S9), and this effect is displayed byusing the display unit 5 (step S10). Then, a series of operation(operating) condition detection procedures has been completed.

Further, in the judgment in the step S5, in the case that theperiodicity is detected (i.e., YES in step S5), the maximum value in thedigital envelope signal Sdw is called up from the memory (step S11), andthen, it is judged whether the called-up maximum value exceeds thethreshold value of the maximum value as a threshold value which wasexperimentally preset for the judgment whether any lubrication fault iscaused at the present stage (step S12).

In this judgment, in the case that the called-up maximum value is notless than the threshold value of the maximum value (i.e., YES in stepS12), it is judged that the lubrication fault is caused at the presentstage in the LM system as an object to be diagnosed (step S13), and thiseffect is displayed by using the display unit 5 (step S10). Then, aseries of operation (operating) condition detection procedures has beencompleted.

Next, in the judgment in the step S12, in the case that the called-upmaximum value is less than the threshold value of the maximum value(i.e., NO in step S12), the event ratio mentioned before to the digitalenvelope signal Sdw is called up from the memory (step S14).

Then, in order to judge or discriminate whether there is a possibilityof generation of the flaking or lubrication fault in the LM system asthe object to be diagnosed, it is judged whether or not the called-upevent ratio is not less than the threshold value of the event ratioexperimentally preset (step S15).

Next, in the judgment in step S15, in the case that the called-up eventratio is less than the threshold value of the event ratio (i.e., NO instep S15), it is judged that there is high possibility of causing thelubrication fault at the present stage in the LM system as an object tobe diagnosed (step S17), and this effect is displayed by using thedisplay unit 5 (step S10). Then, a series of operation (operating)condition detection procedures has been completed. Further, the degreeof the lubrication fault judged in the step S17 differs from the degreeof the lubrication fault judged in the step S13, and the former (case ofthe step S17) only judges the possibility of the causing of thelubrication fault, and on the other hand, the latter (case of the stepS13) can judge the surly causing of the lubrication fault.

Moreover, in the judgment in the step S15, in the case that thecalled-up event ratio is not less than the threshold value of the eventratio (i.e., YES in step S15), it is judged that the flaking isgenerated at the present stage in the LM system as an object to bediagnosed (step S16), and this effect is displayed by using the displayunit 5 (step S10). Then, a series of operation (operating) conditiondetection procedures has been completed.

Further, the described series of operation condition detection result isdisplayed, accumulated in the memory in the signal processing unit 4 andthen statistically processed, thereby detecting worsening of theoperating condition and obviating the generation of faults.

As mentioned above, according to the operation of the conditiondiagnosing apparatus S of the present embodiment, since the presentoperating condition of the LM system can be detected by detecting theextended AE wave generated in accordance with the operation of the LMsystem, the operating condition can be detected during the operationthereof in a real time, without disassembling the LM system, whileexcluding influence due to vibration based on the operation of the LMsystem.

Therefore, it becomes possible to foresee the generation or causing offaults in the LM system, thus improving the maneuverability for a userof the LM system and elongating the usable life time thereof andimproving the quality of devices or machineries manufactured byutilizing this LM system.

Furthermore, in the case that the generated digital envelope signal Sdwhas the periodicity and the maximum value of this digital envelopesignal Sdw is not less than the threshold value of the maximum value, itis judged that the LM system now falls in lubrication fault condition,which is then announced, so that the generation of the lubrication faultcondition in the LM system can be precisely detected in a real timeduring the operation thereof.

Still furthermore, in the case that the generated digital envelopesignal Sdw has the periodicity and the maximum value of this digitalenvelope signal Sdw is less than the threshold value of the maximumvalue, and that the event ratio of the digital envelope signal Sdw isless than the threshold value of the event ratio, it is judged that theLM system may have a possibility of falling in the lubrication faultcondition, which is then announced, so that the possibility of thegeneration of the lubrication fault condition in the LM system can beprecisely detected in a real time during the operation thereof.

Still furthermore, in the case that the generated digital envelopesignal Sdw has the periodicity and the maximum value of this digitalenvelope signal Sdw is less than the threshold value of the maximumvalue, and that the event ratio of the digital envelope signal Sdw isnot less than the threshold value of the event ratio, it is judged thatthe flaking is caused in the LM system, which is then announced, so thatthe generation of the flaking in the LM system can be easily andprecisely detected in a real time during the operation thereof.

Still furthermore, in the case that the generated digital envelopesignal Sdw has no periodicity and the effective value of this digitalenvelope signal Sdw is not less than the threshold value of theeffective value, it is judged that the foreign material invades in theLM system, which is then announced, so that the generation of theinvasion of the foreign material into the LM system can be easily andprecisely detected in a real time during the operation thereof.

Still furthermore, in the case that the generated digital envelopesignal Sdw has no periodicity and the effective value of this digitalenvelope signal Sdw is less than the threshold value of the effectivevalue, it is judged that the LM system is now in the normally operatingcondition, which is then announced, so that the it can be easily andprecisely detected in a real time whether the operating condition at thedigital envelope signal Sdw is normal or not.

Further, by recording a program corresponding to the flowchart shown inFIG. 7 to an information recording medium such as flexible disk or harddisk, or recording the program obtained by means of network such asinternet, and reading out and then executing the program by ageneral-use (general) micro-computer, this micro-computer can beoperated as the signal processing unit 4 in this embodiment. In thiscase, the AE sensor 1, the waveform shaping unit 2 and the A/D converter3, which are mentioned hereinbefore, will be connected to themicro-computer as external-type devices.

Furthermore, in the above-mentioned embodiment, the condition detectionapparatus S shown in FIG. 2 is constructed as an apparatus having singlestructure, and more specifically, this embodiment is applied to a casethat the present condition diagnosis apparatus S is carried to a sitesuch as factory in which the LM system as the object to be diagnosed andis utilized at that site for detecting and diagnosing the operatingcondition of the LM system.

Further, other than the above-mentioned embodiment, the conditiondetection apparatus S of this embodiment may be applied to a case ofdetecting and diagnosing the operating condition of the LM system byusually providing the condition diagnosing apparatus S to a site such asfactory in which the LM system as the object to be diagnosed are set andremotely controlling the condition diagnosing apparatus S through atelephone line or like by a diagnosing staff from an isolated position.

Furthermore, the present invention may be applied to a case that thecondition diagnosing apparatus S is usually provided to a site such asfactory in which the LM system as the object to be diagnosed is set andused, the operating condition of the LM system is automatically detectedand diagnosed in the condition diagnosing apparatus S, in parallel tothis operation, the detected result is transferred to another place,then accumulated there, and an accumulative fault diagnosing is executedon the basis of the accumulated detected result.

Still furthermore, in the described embodiment, although the conditiondetection apparatus S is composed such that one waveform shaping unit 2,one A/D converter 3, one signal processing unit 4 and one display unit 5are utilized for one AE sensor 1, there may be provided another exampleof the structure, other than the above, in which the detection signalsSae from a plurality of AE sensors 1 are inputted through a switchingcircuit into one waveform shaping unit 2 and processed by utilizing onewaveform shaping unit 2, one A/D converter 3, one signal processing unitand one display unit 5. In such example, it becomes necessary tosynchronize the executing timing of the detection processing utilizingthe waveform shaping unit 2, the A/D converter 3, the signal processingunit 4 and the display unit 5 with the take-in timing of the detectionsignal Sae from the corresponding AE sensor 1.

EXAMPLES

A specific example will be shown hereunder with respect to the frequencyanalysis value, the threshold value of the effective value, thethreshold value of the maximum value and the threshold value of theevent ratio, all mentioned hereinbefore, as the basis of the judgmentsin the steps S5, S7, S12 and S15, respectively.

Further, it is to be noted that examples of the respective thresholdvalues shown hereunder are ones in the case where a mold of mold numberSN55LR manufactured by the applicant is utilized as LM guide to whichthe AE sensor is set, an external load to the movable block is 0.1 C (14kN), a stroke as moving distance of the movable block is 250 mm, amoving speed thereof is 24 m/min., the DTE26-type lubrication oilmanufactured by Moville Oil. Ltd. is supplied as lubrication oilintermittently by a constant amount, a sample rate to the detectionsignal Sae is 10 kHz, and a measuring time is 0.4 second.

In accordance with the above respective conditions, as one example ofthe frequency analysis value, it is judged to have the periodicity in acase that a square voltage value (so-called V2 value) obtained throughthe FFT conversion of the digital envelope signal Sdw and, then,frequency analysis (power spectrum) exceeds 1.0×10⁻⁹ (V2), and on theother hand, in a case of less than this value, it is judged not to havethe periodicity.

Further, as one example of the threshold value of the effective value,as the effective value at the digital envelope signal Sdw, a value of1.0×10⁻⁴ (V) is suitable.

Furthermore, as one example of the threshold value of the maximum value,as the maximum value at the digital envelope signal Sdw, a value of2.0×10⁻³ (V) is suitable.

Finally, as one example of the threshold value of the event ratio, 5 to7 times, at which the threshold value of the event ratio shows a valuehigher than a value of 5.0×10⁻⁴ (V) at the digital envelope signal Sdwis suitable.

Further, the respective values in the above examples specifically changein accordance with the change of conditions, excluding the load withrespect to the movable block and the stroke of the movable block fromthe conditions mentioned hereinabove.

Possibility of Industrial Usage

As mentioned above, according to the invention of claim 1, since thewave motion elastically generated by the operation of the linear rollingmotion guide apparatus is detected to thereby detect the presentoperating condition thereof, the operating condition of the linearrolling motion guide apparatus can be detected in a real time withoutdisassembling the apparatus while excluding influence of vibrationcaused by the operation of the apparatus.

Accordingly, the generation of a fault in the linear rolling motionguide apparatus can be foreseen, whereby the maintenance performance ofthe user using the linear rolling motion guide apparatus can beimproved. In addition, the usable life time thereof can be elongated,and apparatus, machineries and the like manufactured by utilizing suchlinear rolling motion guide apparatus can be improved in theirqualities.

According to the invention of claim 2, in addition to the effects of theinvention of claim 1, in the case when the generated detected signal hasthe periodicity and the maximum value at the detected signal is not lessthan the threshold value of the maximum value, it is judged that thelinear rolling motion guide apparatus falls in a lubrication faultcondition and that fact is then announced, so that the generation of thelubrication fault in the linear rolling motion guide apparatus can beeasily and precisely detected in a real time during the operation of theapparatus.

According to the invention of claim 3, in addition to the effects of theinvention of claim 1, when the generated detected signal has theperiodicity, the maximum value in the detected signal is less than thethreshold value of the maximum value and the detected event ratio isless than the threshold value of the event value, it is judged that thelinear rolling motion guide apparatus is in a possibility of falling ina lubrication fault condition and that fact is then announced, so thatthe possibility of the generation of the lubrication fault in the linearrolling motion guide apparatus can be detected easily and precisely in areal time during the operation of the apparatus.

According to the invention of claim 4, in addition to the effects of theinvention of claim 1, when the generated detected signal has theperiodicity, the maximum value in the detected signal is less than thethreshold value of the maximum value and the detected event ratio is notless than the threshold value of the event value, it is judged that aflaking is generated in the linear rolling motion guide apparatus andthat fact is then announced, so that the generation of the flaking inthe linear rolling motion guide apparatus can be detected easily andprecisely in a real time during the operation of the apparatus.

According to the invention of claim 5, in addition to the effects of theinvention of claim 1, when the generated detected signal has noperiodicity, and the effective value in the detected signal is not lessthan the threshold value of the effective value, it is judged that aforeign material is invaded in the linear rolling motion guide apparatusand that fact is then announced, so that the generation of the case ofthe invasion of the foreign material in the linear rolling motion guideapparatus can be detected easily and precisely in a real time during theoperation of the apparatus.

According to the invention of claim 6, in addition to the effects of theinvention of claim 1, when the generated detected signal has noperiodicity and the effective value in the detected signal is less thanthe threshold value of the effective value, it is judged that thepresent operating condition is normal and that fact is then announced,so that it can be detected easily and precisely in a real time whetheror not the operating condition in the linear rolling motion guideapparatus is normal.

According to the invention of claim 7, since the wave motion elasticallygenerated by the operation of the linear rolling motion guide apparatusis detected to thereby detect the present operating condition thereof,the operating condition of the linear rolling motion guide apparatus canbe detected in a real time without disassembling the apparatus whileexcluding influence of vibration caused by the operation of theapparatus.

Accordingly, the generation of a fault in the linear rolling motionguide apparatus can be foreseen, whereby the maintenance performance ofthe user using the linear rolling motion guide apparatus can beimproved. In addition, the usable life time thereof can be elongated,and apparatus, machineries and the like manufactured by utilizing suchlinear rolling motion guide apparatus can be improved in theirqualities.

According to the invention of claim 8, in addition to the effect ofclaim 7, in the case when the generated detected signal has theperiodicity and the maximum value at the detected signal is not lessthan the threshold value of the maximum value, it is judged that thelinear rolling motion guide apparatus falls in a lubrication faultcondition and that fact is then announced, so that the generation of thelubrication fault in the linear rolling motion guide apparatus can beeasily and precisely detected in a real time during the operation of theapparatus.

According to the invention of claim 9, in addition to the effect ofclaim 7, when the generated detected signal has the periodicity, themaximum value in the detected signal is less than the threshold value ofthe maximum value and the detected event ratio is less than thethreshold value of the event value, it is judged that the linear rollingmotion guide apparatus is in a possibility of falling in a lubricationfault condition and that fact is then announced, so that the possibilityof the generation of the lubrication fault in the linear rolling motionguide apparatus can be detected easily and precisely in a real timeduring the operation of the apparatus.

According to the invention of claim 10, in addition to the effect ofclaim 7, when the generated detected signal has the periodicity, themaximum value in the detected signal is less than the threshold value ofthe maximum value and the detected event ratio is not less than thethreshold value of the event value, it is judged that a flaking isgenerated in the linear rolling motion guide apparatus and that fact isthen announced, so that the generation of the flaking in the linearrolling motion guide apparatus can be detected easily and precisely in areal time during the operation of the apparatus.

According to the invention of claim 11, in addition to the effect ofclaim 7, when the generated detected signal has no periodicity, and theeffective value in the detected signal is not less than the thresholdvalue of the effective value, it is judged that a foreign material isinvaded in the linear rolling motion guide apparatus and that fact isthen announced, so that the generation of the case of the invasion ofthe foreign material in the linear rolling motion guide apparatus can bedetected easily and precisely in a real time during the operation of theapparatus.

According to the invention of claim 12, in addition to the effect ofclaim 7, when the generated detected signal has no periodicity and theeffective value in the detected signal is less than the threshold valueof the effective value, it is judged that the present operatingcondition is normal and that fact is then announced, so that it can bedetected easily and precisely in a real time whether or not theoperating condition in the linear rolling motion guide apparatus isnormal.

According to the invention of claim 13, by reading out and executing theprogram for the condition detection by using the computer, the computerfunctions so as to detect the wave motion elastically generated by theoperation of the linear rolling motion guide apparatus and to therebydetect the present operating condition thereof, so that the operatingcondition of the linear rolling motion guide apparatus can be detectedin a real time without disassembling the apparatus while excludinginfluence of vibration caused by the operation of the apparatus.

Accordingly, the generation of a fault in the linear rolling motionguide apparatus can be foreseen, whereby the maintenance performance ofthe user using the linear rolling motion guide apparatus can beimproved. In addition, the usable life time thereof can be elongated,and apparatus, machineries and the like manufactured by utilizing suchlinear rolling motion guide apparatus can be improved in theirqualities.

According to the invention of claim 14, the program for the conditiondetection of claim 13 is recorded to be readable by the computer, and byreading out and executing the program for the condition detection byutilizing the computer, the computer functions so as to detect the wavemotion elastically generated by the operation of the linear rollingmotion guide apparatus and to thereby detect the present operatingcondition thereof, so that the operating condition of the linear rollingmotion guide apparatus can be detected in a real time withoutdisassembling the apparatus while excluding influence of vibrationcaused by the operation of the apparatus.

1. A condition detection apparatus for detecting a present operation condition in a linear rolling motion guide apparatus comprising: detection means for detecting a wave motion elastically generated on the basis of at least either one of contact or collision of a movable member or a track member to a rolling member contained in the linear rolling motion guide apparatus, contact or collision of a rolling surface to the rolling member contained in the linear rolling motion guide apparatus, or mutual contact or collision of the rolling members themselves, at a time when a plurality of rolling members contained in the linear rolling motion guide apparatus revolve in a circulation section therein, and generating an electric detection signal in accordance with the detected wave motion; and judgment means for judging a content of the present operation condition in response to the generated detection signal, wherein said judgment means comprises periodicity judgment means for judging presence or absence of a periodicity in the generated detection signal.
 2. The condition detection apparatus according to claim 1, wherein said judgment means further comprises: maximum value detection means for detecting a maximum value in the generated detection signal at a time when it is judged that the periodicity is present; maximum value judgment means for judging whether or not the detected maximum value is not less than a preliminarily set threshold value of the maximum value; and condition judgment means for judging that, when the detected maximum value is not less than the threshold value of the maximum value, the linear rolling motion guide apparatus falls in a lubrication fault condition, and then announcing that fact.
 3. The condition detection apparatus according to claim 1, wherein said judgment means further comprises: maximum value detection means for detecting a maximum value in the generated detection signal at a time when it is judged that the periodicity is present; maximum value judgment means for judging whether or not the detected maximum value is not less than a preliminarily set threshold value of the maximum value; event ratio detection means for detecting an event ratio in the generated detection signal at a time when the detected maximum value is less than a threshold value of the maximum value; event ratio judgment means for judging whether or not the detected event ratio is not less than a preliminarily set threshold value of the event ratio; and condition judgment means for judging that, when the detected event ratio is less than the threshold value of the event value, the linear rolling motion guide apparatus is in a possibility of falling in a lubrication fault condition, and then announcing that fact.
 4. The condition detection apparatus according to claim 1, wherein said judgment means further comprises: maximum value detection means for detecting a maximum value in the generated detection signal at a time when it is judged that the periodicity is present; maximum value judgment means for judging whether or not the detected maximum value is not less than a preliminarily set threshold value of the maximum value; event ratio detection means for detecting an event ratio in the generated detection signal at a time when the detected maximum value is less than a threshold value of the maximum value; event ratio judgment means for judging whether or not the detected event ratio is not less than a preliminarily set threshold value of the event ratio; and condition judgment means for judging that, when the detected event ratio is not less than the threshold value of the event value, a flaking is generated in the linear rolling motion guide apparatus, and then announcing that fact.
 5. The condition detection apparatus according to claim 1, wherein said judgment means further comprises: effective value detection means for detecting an effective value of the detected detection signal at a time when it is judged that the periodicity is absent; effective value judgment means for judging whether or not the detected effective value is not less than a preliminarily set threshold value of the effective value; and condition judgment means for judging that, when the detected effective value is not less than the threshold value of the effective value, a foreign material invades in the linear rolling motion guide apparatus, and then announcing that fact.
 6. The condition detection apparatus according to claim 1, wherein said judgment means further comprises: effective value detection means for detecting an effective value of the detected detection signal at a time when it is judged that the periodicity is absent; effective value judgment means for judging whether or not the detected effective value is not less than a preliminarily set threshold value of the effective value; and condition judgment means for judging that, when the detected effective value is less than the threshold value of the effective value, a present operation condition is normal, and then announcing that fact.
 7. A condition detection method for detecting a present operation condition in a linear rolling motion guide apparatus comprising: a detection step for detecting a wave motion elastically generated on the basis of at least either one of contact or collision of a movable member or a track member to a rolling member contained in the linear rolling motion guide apparatus, contact or collision of a rolling surface to the rolling member contained in the linear rolling motion guide apparatus, or mutual contact or collision of the rolling members themselves, at a time when a plurality of rolling members contained in the linear rolling motion guide apparatus revolve in a circulation section therein, and generating an electric detection signal in accordance with the detected wave motion; and a judgment step for judging a content of the present operation condition in response to the generated detection signal, wherein said judgment step comprises a periodicity judgment step for judging presence or absence of a periodicity in the generated detection signal.
 8. The condition detection method according to claim 7, wherein said judgment step further comprises: a maximum value detection step for detecting a maximum value in the generated detection signal at a time when it is judged that the periodicity is present; a maximum value judgment step for judging whether or not the detected maximum value is not less than a preliminarily set threshold value of the maximum value; and a condition judgment step for judging that, when the detected maximum value is not less than the threshold value of the maximum value, the linear rolling motion guide apparatus falls in a lubrication fault condition, and then announcing that fact.
 9. The condition detection method according to claim 7, wherein said judgment step further comprises: a maximum value detection step for detecting a maximum value in the generated detection signal at a time when it is judged that the periodicity is present; a maximum value judgment step for judging whether or not the detected maximum value is not less than a preliminarily set threshold value of the maximum value; an event ratio detection step for detecting an event ratio in the generated detection signal at a time when the detected maximum value is less than a threshold value of the maximum value; an event ratio judgment step for judging whether or not the detected event ratio is not less than a preliminarily set threshold value of the event ratio; and a condition judgment step for judging that, when the detected event ratio is less than the threshold value of the event value, the linear rolling motion guide apparatus is in a possibility of falling in a lubrication fault condition, and then announcing that fact.
 10. The condition detection method according to claim 7, wherein said judgment step further comprises: a maximum value detection step for detecting a maximum value in the generated detection signal at a time when it is judged that the periodicity is present; a maximum value judgment step for judging whether or not the detected maximum value is not less than a preliminarily set threshold value of the maximum value; an event ratio detection step for detecting an event ratio in the generated detection signal at a time when the detected maximum value is less than a threshold value of the maximum value; an event ratio judgment step for judging whether or not the detected event ratio is not less than a preliminarily set threshold value of the event ratio; and a condition judgment step for judging that, when the detected event ratio is not less than the threshold value of the event value, a flaking is generated in the linear rolling motion guide apparatus, and then announcing that fact.
 11. The condition detection method according to claim 7, wherein said judgment step further comprises: an effective value detection step for detecting an effective value of the detected detection signal at a time when it is judged that the periodicity is absent; an effective value judgment step for judging whether or not the detected effective value is not less than a preliminarily set threshold value of the effective value; and a condition judgment step for judging that, when the detected effective value is not less than the threshold value of the effective value, a foreign material invades in the linear rolling motion guide apparatus and then announcing that fact.
 12. The condition detection method according to claim 7, wherein said judgment step further comprises: an effective value detection step for detecting an effective value of the detected detection signal at a time when it is judged that the periodicity is absent; an effective value judgment step for judging whether or not the detected effective value is not less than a preliminarily set threshold value of the effective value; and a condition judgment step for judging that, when the detected effective value is less than the threshold value of the effective value, a present operation condition is normal and then announcing that fact.
 13. A computer-readable medium having a computer program executable by a computer to perform the judgment means of claim
 1. 